perf tools: Use __maybe_used for unused variables

perf defines both __used and __unused variables to use for marking
unused variables. The variable __used is defined to
__attribute__((__unused__)), which contradicts the kernel definition to
__attribute__((__used__)) for new gcc versions. On Android, __used is
also defined in system headers and this leads to warnings like: warning:
'__used__' attribute ignored

__unused is not defined in the kernel and is not a standard definition.
If __unused is included everywhere instead of __used, this leads to
conflicts with glibc headers, since glibc has a variables with this name
in its headers.

The best approach is to use __maybe_unused, the definition used in the
kernel for __attribute__((unused)). In this way there is only one
definition in perf sources (instead of 2 definitions that point to the
same thing: __used and __unused) and it works on both Linux and Android.
This patch simply replaces all instances of __used and __unused with
__maybe_unused.

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1347315303-29906-7-git-send-email-irina.tirdea@intel.com
[ committer note: fixed up conflict with a116e05 in builtin-sched.c ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 15 insertions, 14 deletions

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index c350cfee3157..6d98a83d5a60 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -430,9 +430,9 @@ static void process_event(union perf_event *event, struct perf_sample *sample,
 	printf("\n");
 }
 
-static int default_start_script(const char *script __unused,
-				int argc __unused,
-				const char **argv __unused)
+static int default_start_script(const char *script __maybe_unused,
+				int argc __maybe_unused,
+				const char **argv __maybe_unused)
 {
 	return 0;
 }
@@ -442,8 +442,8 @@ static int default_stop_script(void)
 	return 0;
 }
 
-static int default_generate_script(struct pevent *pevent __unused,
-				   const char *outfile __unused)
+static int default_generate_script(struct pevent *pevent __maybe_unused,
+				   const char *outfile __maybe_unused)
 {
 	return 0;
 }
@@ -474,7 +474,7 @@ static int cleanup_scripting(void)
 
 static const char *input_name;
 
-static int process_sample_event(struct perf_tool *tool __used,
+static int process_sample_event(struct perf_tool *tool __maybe_unused,
 				union perf_event *event,
 				struct perf_sample *sample,
 				struct perf_evsel *evsel,
@@ -534,7 +534,7 @@ static struct perf_tool perf_script = {
 
 extern volatile int session_done;
 
-static void sig_handler(int sig __unused)
+static void sig_handler(int sig __maybe_unused)
 {
 	session_done = 1;
 }
@@ -644,8 +644,8 @@ static void list_available_languages(void)
 	fprintf(stderr, "\n");
 }
 
-static int parse_scriptname(const struct option *opt __used,
-			    const char *str, int unset __used)
+static int parse_scriptname(const struct option *opt __maybe_unused,
+			    const char *str, int unset __maybe_unused)
 {
 	char spec[PATH_MAX];
 	const char *script, *ext;
@@ -690,8 +690,8 @@ static int parse_scriptname(const struct option *opt __used,
 	return 0;
 }
 
-static int parse_output_fields(const struct option *opt __used,
-			    const char *arg, int unset __used)
+static int parse_output_fields(const struct option *opt __maybe_unused,
+			    const char *arg, int unset __maybe_unused)
 {
 	char *tok;
 	int i, imax = sizeof(all_output_options) / sizeof(struct output_option);
@@ -982,8 +982,9 @@ static char *get_script_root(struct dirent *script_dirent, const char *suffix)
 	return script_root;
 }
 
-static int list_available_scripts(const struct option *opt __used,
-				  const char *s __used, int unset __used)
+static int list_available_scripts(const struct option *opt __maybe_unused,
+				  const char *s __maybe_unused,
+				  int unset __maybe_unused)
 {
 	struct dirent *script_next, *lang_next, script_dirent, lang_dirent;
 	char scripts_path[MAXPATHLEN];
@@ -1172,7 +1173,7 @@ static int have_cmd(int argc, const char **argv)
 	return 0;
 }
 
-int cmd_script(int argc, const char **argv, const char *prefix __used)
+int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused)
 {
 	char *rec_script_path = NULL;
 	char *rep_script_path = NULL;